1. Field
The following description relates to a humidity sensor formed by voids within interconnects and a method of manufacturing the same. The accuracy with respect to the measurement of the humidity sensor is improved by depositing a humidity sensing material to detect humidity inside the voids. Accordingly, manufacturing costs can be reduced.
2. Description of Related Art
Recently, research for humidity sensor using a smart device has increased. Significant research is focused on Ubiquitous Sensor Network (USN) systems and Internet of Things (IoT) technologies to control the entire system based on the data provided from each sensor module. A humidity sensor that can be manufactured at low costs and has accuracy higher than the typical sensors is needed.
For the humidity sensor using a Chip Scale Packaging (CSP) or a Wafer Level Chip Scale Packaging (WLCSP), it is important to maintain a structure in which a top surface is planar to minimize stress which can lead to poor reliability. To this end, a passivation layer and a stress relief layer are needed. Such humidity sensors are typically based on capacitance sensor electrodes. A technique that maximizes an area of the electrode is needed in order to maximize the sensitivity.
However, the above configured structures and methods are few. Further, higher manufacturing costs are required to improve the sensitivity of the humidity than that of typical devices.